Many of the bolded characters in the characterization above are apomorphies of subsets of streptophytes along the lineage leading to the embryophytes, not apomorphies of crown-group embryophytes per se.

All groups below are crown groups, nearly all are extant. Characters mentioned are those of the immediate common ancestor of the group, [] contains explanatory material, () features common in clade, exact status unclear.

Evolution.Genes & Genomes. Based on a study of the genome of Arabidopsis, De Bodt et al. (2005, see also Maere et al. 2005) suggest there was a duplication of the whole genome some 109-66 m.y. before present, although given the uncertainty over the dating of this duplication and relationships within rosids, exactly where the duplication should go on the tree is unclear. Placing it at this node is one possibility.

For integument thickness, a possible apomorphy, which, however, reverses, and its condition is unclear in Huerteales, etc., see Endress and Matthew (2006a).

Phylogeny. Relationships between the malvid clades are somewhat uncertain. The clade [Malvales + Sapindales] may be sister group to Brassicales (Soltis et al. 2000; Peng et al 2003: both weak support; Bell et al. 2010), and Endress and Matthews (2006) note that there are some features perhaps more common in these first two families than elsewhere in this affinity. Other studies suggest that [Malvales + Sapindales] may be sister to [Brassicales + Tapisciales] (Soltis et al. 2007a: support weak for the latter pair; Bell et al. 2010). Although Bausher et al. (2006) in an analysis of whole chloroplast genomes found strong support for the clade [Brassicales + Malvales], only one species from the three larger orders and no Huerteales were included (see also S.-B. Lee et al. 2006: sampling even more exiguous; Jansen et al. 2007; Moore et al. 2007). There was also some support for this topology in analyses by Savolainen et al. (2000) and Hilu et al. (2003). Alford (2006), when describing his Gerrardinaceae, found that Huerteales (Perrottetia not included), Brassicales and Malvales formed a polytomy, the combined group being rather poorly supported as sister to Sapindales, while Worberg et al. (2007b, 2009) recovered the relationships [Sapindales [Huerteales [Brassicales + Malvales]]], with strong support, and they found that each of the four orders was monophyletic. In studies including the mitochondrial matR gene, although the malvid clade was recovered, relationships within it were unclear (Zhu et al. 2007). I follow Worberg et al. (2009).

Note: Possible apomorphies are in bold. However, the actual level at which many of these features, particularly the more cryptic ones, should be assigned
is unclear. This is partly because many characters show considerable homoplasy, in addition, basic information for all too many is very incomplete, frequently coming from taxa well embedded in the clade of interest and so making the position of any putative apomorphy uncertain. Then there is the not-so-trivial issue of how ancestral states are reconstructed (see above).

Pollination Biology. There is notable variation in dichogamy here, see e.g. Bertin and Newman (1993), Routley et al. (2004).Plant-Animal Interactions. Associated with the accumulation of noxious secondary metabolites, specialised herbivores are found on many of this group. Thus the hemipteran Calophya eats largely Anacardiaceae, Burseraceae, Simaroubaceae and Rutaceae (Burckhardt & Basset 2000) - plus a couple of records from entirely unrelated families. A notable diversity of monoterpene synthase genes have been found in Sapindales studied, and the products of these genes may be involved either directly in plant defence, or indirectly by signalling to parasitoids of herbivores, but studies of these genes are currently only preliminary (Zapata & Fine 2013 and references). Galls are quite common, perhaps especially on Sapindaceae and Anacardiaceae (Mani 1964).

Chemistry, Morphology, etc. Gums and resins occur in both the Rutaceae-Meliaceae-Simaroubaceae and Burseraceae-Anacardiaceae groups (Nair 1995).

Stratified phloem may be quite widespread (in some Meliaceae, Burseraceae and Simaroubaceae, at least: M. Ogburn, pers. comm.), also Sapindaceae. Teeth, when present, have a clear glandular apex broadening distally and with a foramen and two accessory veins (or one, the other going above the tooth: Hickey & Wolfe 1975). The stipules are sometimes clearly modified leaflets and have been described as pseudostipules or metastipules, the latter being defined as structures having the morphology of true stipules, yet there was good reason to believe that they were derived from pseudostipules... (Weberling & Leenhouts 1965).

Bachelier and Endress (2009) note some floral developmental features found widely in this clade, while Yamamoto et al. (2014: esp. Table S1) compare embryological features; for some details of embryology, see also Mauritzon (1936). Inconspicuous oblique monosymmetry may be common in the order, although many Sapindaceae, for example, are more strongly monosymmetric. The flowers are often imperfect, but since staminate and carpellate flowers have well-developed
pistillodes and staminodes respectively, they can be difficult to distinguish. The rather uncommon feature of floral tubes that are formed by connate or closely adpressed and flattened filaments occur throughout Meliaceae, in a number of Rutaceae, and in Boswellia dioscorides (Burseraceae). Pollen with striate exine is scattered through the order. Septal cavities have been noticed in Cneorum (Rutaceae) and Koelreuteria (Sapindaceae), but they do not secrete nectar (Caris et al. 2006, c.f. septal nectaries in monocots).

Nitrariaceae are particularly poorly known.

Phylogeny. For general relationships, see Gadek et al. (1996), while Pell (2004) notes some deletions and insertions that may characterise groupings within the clade. Muellner et al. (2007) present a two-gene tree with quite good sampling; their results, albeit poorly supported, suggest the basal relationships in the tree here (also poorly supported in Soltis et al. 2011), a fair bit of resolution elsewhere, excepting only a moderately-supported sister group relationship between Meliaceae and Simaroubaceae (c.f. Gadek et al. 1996; Soltis et al. 2011: sampling), so a trichotomy including Rutaceae is shown on the tree. Relationships are somewhat different in Wang et al. (2009), but support was weak and sampling poor.

Molecular data early placed Biebersteinia, ex Geraniaceae, in Sapindales, albeit with a long branch (Bakker et al. 1998). Its herbaceous habit is rather unusual for Sapindales, but its ethereal oils
(no oxygenated sequiterpenes, high proportion of aliphatic hydrocarbons - Bate Smith 1973; Greenham et al. 2001), single
ovule/carpel, etc., are all congruent with a position here.

Previous Relationships. In the past Bretschneideraceae and Akaniaceae (= Akaniaceae, see Brassicales here) have been associated with Sapindales, Bretschneidera in particular looking very like a member of Sapindaceae; at the time, the presence of myrosin cells in the former was not considered to be all that important (Cronquist 1981; Takhtajan 1997).

Age. The age of crown-group Biebersteiniaceae is estimated as 63.3-54.8 m.y. (Muellner et al. 2007).

Biebersteiniaceae are perennial, glandular-hairy herbs that have odd-pinnate leaves with lobed to compound leaflets and petiolar stipules. Ihe inflorescence is erect and racemose and the flowers are large. The fruit has a single seed per carpel and a persistent columella.

Evolution.Pollination and Seed Dispersal. Yamamoto et al. (2014) note distinctive changes in the gynoecium as it develops; at the time of pollination the nucellus apex is exposed.

Chemistry, Morphology, etc. At least some species of Biebersteinia are foul-smelling.

The ante-petalous stamens are longest. Takhtajan
(1997) described the ovules as being unitegmic. There is an apparent similarity of the seed coat of Biebersteinia and that of Vivianaceae (Geraniales), especially when young, since both exotesta and endotegmen are tanniniferous (Boesewinkel 1988, 1997). However, Boesewinkel (1988, 1997) thought that the ovules were bitegmic and the micropyle was bistomal; c.f. Yamamoto et al. (2014).

Evolution.Divergence & Distribution. Given the phylogeny of the family, the distinctive flowers and fruits of Tetradiclis may be derived.

Ecology & Physiology. Members of this family are often to be found in salt deserts.

Chemistry, Morphology, etc. The variation in this group is rather puzzling. Takhtajan (1997) says that stipules
are absent in Tetradiclis; they are present, if small.

Bachelier et al. (2011) discuss floral morphology in detail, attempting to clarify features like androecial morphology that had been interpreted in various ways in earlier literature. The androecium of Peganum is described as being obdiplostemonous by Eckert (1966); the 15 stamens may be in groups of three opposite the sepals, or there may be paired stamens opposite the petals (Ronse Decraene & Smets 1991a, 1992, 1996a; Ronse Decraene 1992; Ronse Decraene et al. 1996). No endothelium has been recorded in members of Nitrariaceae (Kapil & Tiwari 1978), c.f. Zygophyllaceae s. str..

For general information, see Weberling and Leenhouts (1965), Hussein et al. (2009) and Sheahan (2011: as Nitrariaceae and Tetradiclidaceae); for chemistry, see Hegnauer (1973, 1990: as Zygophyllaceae), Sheahan and Cutler (1993) provide details of anatomy, Bachelier et al. (2011: nice study, all three genera) of floral morphology; for the embryology of Peganum, see Kapil and Ahluwalia (1963), and of Tetradiclis, see Kamelina (1994), for endosperm development, etc., see Batygina et al. (1985), and for seed anatomy, see Danilova
(1996).

Previous Relationships. Nitrariaceae and Zygophyllaceae agree in general appearance, wood anatomy, and perhaps also chemistry (Nag et al. 1995); since both grow in dry and warm habitats, this may account for some of these similarities. Indeed, the two families used to be placed in an expanded Zygophyllaceae (Cronquist 1981), while Takhtajan (1997) included the genera in Nitrariaceae as three separate families in his Zygophyllales. Zygophyllales-Zygophyllaceae here are not remotely close to Nitrariaceae.

Age. The age of this node is somewhere around 93.6, 83.6 or 74.1 m.y. (Muellner et al. 2007), or (127-)116(-105) m.y. (Weeks et al. 2014).

Evolution.Ecology & Physiology. All families in this clade (bar Kirkiaceae) are common tress at least 10 cm across in Amazonian forests and have at least one of the 227 species that make up half the stems in Amazonian forests (for a total of 24 species; ter Steege et al. 2013).

Chemistry, Morphology, etc. Syllepsis is uncommon in this clade (Keller 1994). For some general information, see Bachelier and Endress (2008b).

Kirkiaceae are woody plants that have often rather closely-set odd-pinnate leaves with toothed leaflets. Ihe inflorescence is dichasial, although the ultimate branches may be monochasial, and the flowers are small and 4-merous. The fruit is a ridged or angled schizocarp with persistent if slender columellar strands.

Chemistry, Morphology, etc. The family is chemically unexceptionable, lacking distinctive secondary metabolites found elsewhere in the order (Mulholland et al. 2003). The wood of Pleiokirkia is reported to smell like honey (Schatz 2001).The lower order inflorescence branches have carpellate flowers, while flowers on higher order branches are male (Bachelier & Endress 2008b). The endocarp of the fruit has elongated and variously oriented sclereids (Fernando & Quinn 1992).

For some information on anatomy, see Jadin (1901), and on chemistry, see Nooteboom (1967); for the floral morphology of Kirkia, see Bachelier & Endress (2008a, esp. b). For general information, see Muellner (2011).

Previous Relationships. Kirkiaceae were previously placed in (Cronquist 1983, but with some doubt) or near Simaroubaceae (Takhtajan 1997), but they lack quassinoids and limonoids.

Fossils assignable to Burseraceae/Anacardiaceae are known from the early Eocene in England ca 50 m.y.a. (Collinson & Cleal 2001).

Evolution.Divergence & Distribution. Weeks et al. (2014) compared the path of evolution in Burseraceae and Anacardiaceae, clades of the same age and about the same size, noting the comparatively greater diversity of fruit morphologies and expanded climatic tolerances in the latter (see also Donoghue & Edwards 2014 for biome shifts).

Chemistry, Morphology, etc. Anacardiaceae like
Pachycormus have thin, brown, flaking bark that looks quite
like that of Burseraceae; the wood anatomy of the two is very similar (Daly et al. 2011).

Bachelier and Endress (2009) discuss the floral morphology and anatomy of this clade in detail. The basic endocarp condition for [Anacardiaceae + Burseraceae] seems to be that of an unoriented mass of sclerified and often crystalliferous cells (Wannan & Quinn 1990), as found in Anacardiaceae-Spondiadoideae, and also in Buchanania, Campnosperma and Pentaspadon, included in Anacardioideae, as by Pell (2004: Campnosperma not sequenced), as well as in Burseraceae. An operculum may be derived twice in Anacardiaceae (Pell & Urbatsch 2001), but it is also found in fruits of Burseraceae and perhaps it, too, is plesiomorphic within the whole clade.

For chemistry, see Hegnauer (1964, 1989), for general developmental information, see Bachelier and Endress (2007a, especially 2008a, b).

Anacardiaceae may be fairly readily recognised because of their often
black and/or rather resinous-smelling exudate; the leaves often have black discolorations and the blade
may dry a distinctive grey colour. In herbarium specimens, the dry, black exudate may entirely cover the cut surface of the twig, or it may form a distinctive black ring around the periphery. The leaves are often odd-pinnate and the leaflets are opposite to alternate. The flowers are small, and the fruits often have an excentric style or styles (e.g. Spondias!) and are
often more or less flattened and single-seeded drupes.

Evolution.Divergence & Distribution. For the early Caenozoic fossil history of what are now East Asian endemic Anacardiaceae, see Manchester et al. (2009) - Choerospondias has been found in Lower Eocene deposits of the London Clay. Middle Eocene deposits from Germany include fossils of the distinctive fruits of the New World Anacardium, with their much-swollen pedicels; the African Fegimanra, sister to Anacardium, also has swollen pedicels, although they are clearly different (Manchester et al. 2007b; Pell et al. 2011; Collinson et al. 2012 for this and other fossil records). On the other hand, distinctive fruits that have been identified as Dracontomelon, a genus now restricted to the Old World, are known from the Late Eocene of Panama in deposits some 40-37 m.y. old (Herrera et al. 2012).

Weeks et al. (2014) emphasized the diversity of fruit dispersal types in the family, the amount of dispersal, and they also noted that the ability to live in cooler (i.e. with some freezing) conditions has evolved here.

Plant-Animal Interactions. Anacardiaceae are noted for the sometimes extremely violent allergenic reactions their exudates cause; catechols, resorcinols and other types of phenolic compounds - often in a mixture, as in urushiol - are involved. About a quarter of the genera, all Anacardioideae, have such compounds (Aguilar-Ortigosa et al. 2003; Aguilar-Ortigosa & Sosa 2004).

Aphids (Fordinae) that form distinctive galls are closely associated with species of Pistacia (Inbar 2009), the sometimes massive, spherical galls producing terpenes that dissuade goats, at least, from eating them (Rostás et al. 2013), and aphid galls form on other Anacardiaceae (Wool 2004). A gall-forming jumping psyllid plant louse, the hemipteran Calophya, is notably common on Schinus, and other psyllids occur on Anacardiaceae (Burckhardt & Basset 2000; Burckhardt 2005).

Pollination Biology & Seed Dispersal. There is chalzogamy in Pistacia, and perhaps other genera, the pollen tube moving from the funicle via the ponticulus, an outgrowth of the funicle that bridges the gap between it and the chalaza (Martínez-Pallé & Herrero 1995; Bachelier & Endress 2009).

Anacardioideae have a number of different kinds of disseminules that have modifications for wind dispersal. These include fruits adnate to broad bracts (Dobinea), fruits with a wing formed by the flattened peduncle of the inflorescence (Amphipterygium), much enlarged sepals (Parishia) or petals (Swintonia), more ordinary samaras (Loxopterygium), while in Cotinus hairs on the pedicels help in the wind dispersal of the fruits. The evolution of these fruit types seems to be correlated with the adoption of a drier habitat (Pell & Mitchell 2007). In Anacardium the fleshy swollen pedicel is part of the attractive unit.

Chemistry, Morphology, etc. Schweingruber et al. (2011) emphasize the abundance of tension wood here. Branching in Anacardium may occur on the current flush.

Hardly surprisingly, wind-pollinated taxa often lack a disc, also petals. Mangifera has one or two stamens borne inside the nectariferous disc; normally the stamens are outside the nectary. In Anacardium
the single stamen is on an oblique plane of symmetry; more generally, the position
of the carpel, when single, suggests that the flower is obliquely symmetric (Ronse de Craene 2010). In Anacardioideae the floral/receptacle apex is sometimes quite short (Bachelier & Endress 2009). Pistacia and Amphipterygium (see Julianaceae below) both are wind pollinated, dioecious, and with reduced flowers. Their ovules are distinctive, being unitegmic and with a massive funicle, etc. (Bachelier & Endress 2007b). For infraspecific variation in style number - 1, 3 - see Gonzàlez and Vesprini (2010). Although the fruits are commonly described as drupes, the origins of the various layers of the fruit wall do not correspond to those of a drupe in the strict sense (Gonzàlez & Vesprini 2010). In Pistacia, at least, the fruit develops well before the seed, so for some time it appears almost empty (Copeland 1955).

For general information, see Ding Hou (1978), Pell et al. (2011) and Michell et al. (2006); Pell (2004) covered the morphology of the whole family in a phylogenetic context. For general chemistry, see Young (1976), for chemistry of Julianaceae, see Hegnauer (1966, 1989), for exudates, see Lambert et al. (2013), for wood anatomy, see Gupta and Agarwal (2008), for floral morphology, Wannan and Quinn (1991), for some embryology, see Grimm (1912), Copeland and Doyel (1940) and Copeland (1955), for fruit anatomy, Wannan and Quinn (1990), for ovules, fruit and seed, see von Teichman and van Wyk (1988 and references), and
for seed anatomy, see von Teichman (1991, 1994, and references).

Phylogeny. Spondiadoideae-Spondiadeae and some Rhoeeae, including Pegia, Tapirira and Cyrtocarpa (see Aguilar-Ortigosa & Sosa 2004; Pell 2004) have been recovered as sister to the rest of the family. However, the situation is now rather complicated. Buchanania in some analyses is quite well supported as sister to other Anacardioideae (Aguilar-Ortigosa & Sosa 2004; Wannan 2006), consistent both with its chemistry, endocarp anatomy (it lacks a stratified endocarp), carpel number of 4-6, and different position of the fertile carpel, but its phylogenetic position is not fixed in other analyses (Pell & Mitchell 2007, c.f. abstract). Campnosperma, initially included in only one study (Chayamarit 1997: sampling limited, relationships different from those in other studies, no support values), has an endocarp similar to that of Buchanania and the fruit is sometimes two-locular; it was not sequenced by Pell (2004). Pell et al. (2011) suggested that Spondiadoideae may be polyphyletic, and Weeks et al. (2014) found that Spondiadoideae were paraphyletic, Campnosperma being between the two parts, Buchanania ending up sister to one of those parts, and Pentaspadon was sister to the whole family - however, support was not strong.

In the remainder of the family, there are four main clades, with [Dobinaea + Campylopetalum] sister to the whole lot, support for the scaffolding is quite good (Weeks et al. 2014). In the old Anacardioideae (Pell & Urbatsch 2000, 2001) wind-dispersed taxa do not form a single group (Pell & Mitchell 2007, c.f. Pell & Urbatsch 2001). For relationships within Rhus, from which the allergenic Toxicodendron, has been excluded, see Andrés-Hernández et al. (2014).

Classification. See Mitchell et al. (2006) for a list of genera; Pell et al. (2011) included 21 genera in their polyphyletic Spondiadoideae. Buchanania and Campnosperma are included in Anacardioideae above, and this robs the subfamily of much in the way of apomorphies, but obviously the current classification is decidedly temporary. For the limits of Rhus, which seem best narrowly drawn (i.e., restricted to ca 35 species), see Yi et al. (2006 and references).

Previous Relationships. A number of anacardiaceous genera have highly reduced flowers and inflorescences, and in the past they have been segregated in separate families. These include Blepharocaryaceae, with their compact, involucrate inflorescences, Julianaceae, dioecious, the staminate flowers with extrorse anthers and carpellate
flowers that lack a perianth but are surrounded by an involucre, and finally Podoaceae, with opposite leaves and carpellate
flowers that also lack a perianth.

Age. De-Nova et al. (2012) dated crown-group Burseraceae to the early Palaeocene (69.7-)64.9(-60.3) m.y.a.; the estimate in Weeks et al. (2005: n.b. in text as the divergence between Anacardiaceae and Burseraceae) is (61.9-)60(-58.1) m.y.a. and in Weeks et al. (2014) the age is (106-)91(-78) m.y.a.; an age of 120 m.y. plus can be estimated from the discussion in Becerra (2005).

Burseraceae are recognisable by their often scented resinous exudate and smooth, flaking bark; compound,
odd-pinnate leaves with opposite, often long-petiolulate and more or less
pulvinate leaflets (especially the terminal leaflet) that have prominent fine venation especially when dry; and petioles, petiolules and rachis that tend to be brownish and more or less scurfy. The calyx is often connate and 3- or 4-lobed, and the angled drupes have a wrinkled
surface when dry. The resinous exudate often smells of almonds (myrrh, frankincense),
and in some genera the leaflets are strikingly symmetric.

Evolution.Divergence & Distribution. Dates for the split between Bursera and Commiphora vary from ca 120 to ca 60 m.y.a. - c.f. Becerra (2005) and Becerra et al. (2012); with the earlier age, distributions could be affected by continental drift. Weeks and Simpson (2007) suggested that divergence of Commiphora from the clade now represented by the E. Asian B. tonkinensis occurred some 53-41.6 m.y.a. in the Eocene; Commiphora itself did not diversify until 32.3-23.2 m.y.a., Neogene aridification of Africa occurring more or less at that time. De-Nova et al. (2012) dated the split between Bursera and Commiphora to (59.0-)54.7(-50.6) m.y., crown group Bursera being ca 49.4. m.y.o., although they thought that diversification within the genus did not really get going until (23-)20 m.y. ago. Becerra et al. (2009) had suggested that Bursera, speciose in the seasonally-dry, tropical forests of Mexico, had diversified most within about the last 25 m.y., while De-Nova et al. (2012) estimated the age of most species of Bursera there at ca 7.5 m.y. - more or less as predicted for species in such forests (Pennington et al. 2009; Dick & Pennington 2011).

Weeks et al. (2005), Weeks and Simpson (2007: much detail) and Weeks et al. (2014) discuss the complex biogeographic relationships within Burseraceae, the latter emphasizing the paucity of biome shifts in the family and the importance of Miocene radiations in both Protieae and Bursereae.

Ecology & Physiology. Burseraceae are a notable component of the Amazonian forests, and include a disproportionally large number of the common tree species with stems at least 10 cm across (ter Steege et al. 2013).

Fine et al. (2014 and references) have studied the diversification of the Protieae, an important element of neotropical forests, in some detail; this began well before the uplift of the Andes. 35 species of Burseraceae, mostly Protium, in the western Amazon largely separated out ecologically, preferring either fertile clay, white sand, or terrace soils (Fine et al. 2005); differentiation of secondary metabolites may also be involved - see also below. In Mexico, Becerra et al. (2009) noted that some 85% of the some 100 species of Bursera, often quite narrowly distributed, were to be found in seasonally-dry tropical forests. De-Nova et al. (2012) suggested that there had been nine shifts to xerophytic scrublands, seven to oak forests, and one to tropical forests, but overall they discussed the habitat preferences of the genus in terms of niche conservatism.

Plant-Animal Interactions. For possible coadaptive relationships between Burseraceae, especially Bursera itself, and herbivorous chrysomelid beetles (Blepharida) and how the latter deal with the toxic terpene-containing resins the plants contain, see Becerra (1997, 2003 and references) and Becerra et al. (2001: particularly interesting). Becerra (2003) suggested that the two had been co-evolving for about 100 m.y., although other estimates for the age of the family (see above) suggest that this figure is very much an over-estimate. Toxic material in Species that have a squirt defence have toxic material under pressure in their tissues, and when these are perforated it is ejected to a diastance of up to 2 m; such species have a rather simple terpenoid-based exudate (Becerra et al. 2009). Locally, species of Bursera tend to be chemically more dissimilar than would be expected at random (Becerra 2007). Overall chemical diversity in Bursera has increased with time/speciation, if dropping off when considered from a per speciation point of view, and terpene variation seems to have become a matter of permuting combinations of chemicals in the local ecological context (Becerra et al. 2009).

Zapata and Fine (2013) found there were 3-5 copies of monoterpene synthase genes in Protium, one copy being very old, the other copies representing duplication events that occurred 50-70 m.y.a., before the diversification of Protieae (Fine et al. 2014). The evidence suggested that the products of these genes might have functions other than direct defence against herbivores, rather, they might attract predators and parasitoids of these herbivores (Zapata & Fine 2013).

Chemistry, Morphology, etc. The remarkable leaf bases of Beiselia are described by Forman et al. (1989); the axillary bud is borne on the base a little way from the stem. Some Burseraceae have foliaceous stipule-like structures; these are usually interpreted as being the reduced basal pair of
leaflets of a compound leaf.

A few genera (e.g. Garuga) have a well-developed
hypanthium; the disc is rarely extrastaminal (Triomma). The odd carpel is drawn as being abaxial
in 4-merous Amyris (Schnizlein 1843-1870, fam. 244). Srivastava (1968) thought that the ovules of Bursera delpechiana were straight, but they do not appear to be so from his illustration. The embryo sac is often very deeply seated in the ovule, with up to 85 cell layers between it and the nucellar epidermis; the shape of the embryo sac at maturity is very variable (Wiger 1935).

For additional general information, see Lam (1931, 1932), Leenhouts (1956), and in particular, Daly et al. (2011). For some chemistry, see Khalid (1983) and Lambert et al. (2013: exudates), for pollen morphology, see Harley and Daly (1995: Protieae) and Harley et al. (2005: considerable variation), for embryology, Narayana (1960 and references), and for pseudaril anatomy, see Ramos-Ordoñez et al. (2013).

Phylogeny. The quite recently-described Beiselia is sister to the rest of the family (Clarkson 2002; Weeks et al. 2005; Thulin et al. 2008). This has considerable implications for character evolution; Beiselia also has several probably autapomorphic features.

In some studies Commiphora was embedded in Bursera, but with weak support (Weeks et al. 2005). Becerra et al. (2012) and De-Nova et al. (2012, but c.f. some analyses in the latter) also found that a monophyletic Bursera was sister to Commiphora; what about B. tonkinensis? Protieae, Bursereae, and Garugeae (the latter including Canarium, etc.) all had strong support individually, but relationships between them were unclear (Thulin et al. 2008); thus although Becerra et al. (2012) suggested the relationships [Canarieae [Protieae + Bursereae]], support for the position of Canarieae was not very strong.

Age. Wikström et al. (2001) dated this node to (61-)57, 55(-51) m.y.a., Magallón and Castillo (2009) suggested an age of around 70.7 m.y., and Bell et al. (2010) an age of (70-)64(-57) or (54-)51(-49) m.y..

Chemistry, Morphology, etc. The style in at least some Rutaceae and Sapindaceae is hollow (Lersten 2004). For an extensive tabulation of variation in anther, ovule and seed characters of this clade, see Tobe (2011a).

Sapindaceae are recognisable by their often spiral, pinnately-compound
leaves with subopposite leaflets and a terminal rhachis tip, although many
taxa have ternately/palmately-compound leaves. The base of the petiole is quite strongly swollen and the stem is ridged. The leaflets may be coarsely serrate and the fine venation is often prominent when dry. The inflorescences are branched,
and the flowers are often borne in congested groups along the axes. The flowers
are often rather small and are conspicuously hairy inside; the nectary is outside the staminal ring and there are often
eight stamens and complex folds or scales on the petals. The fruits have only one or two seeds per
carpel and are often deeply lobed, or a single carpel only may develop, the
other one or two carpels persisting at the base; samaras of various types are
common. The little pocket in the seed coat which encloses the radicle is distinctive.

Evolution.Divergence & Distribution.Cupaniopsis-type pollen is widespread in the fossil record, including from several sites in Africa, although Sapindaceae with such pollen are no longer to be found there (Coetzee & Muller 1984). Wehrwolfea, with striate pollen and a floral formula of K 4 C 4 A 10(?+) G 3-4, is known from the middle Eocene of western Canada (Erwin & Stockey 1990). For the early Caenozoic fossil history of what are now East Asian endemics, see Manchester et al. (2009).

For the biogeography of the family, in which much dispersal is involved, see Buerki et al. (2010c, 2013b). The subfamilies of Sapindaceae spread in the mid Cretaceous 116-98 m.y., initially from Laurasia, with South East Asia remaining an important area in the evolution of the family (Buerki et al. 2010c, 2013b).

Sapindaceae seem to have moved into New Caledonia ca 10 times or more, or there is yet a more complex pattern of movement to and from the island; the relatives of the Mauritian Cossinia pinnata (Dodonaeoideae) grow in the New Caledonian area (Buerki et al. 2012a). The very widespread Dodonaea viscosa has spread within the last two m.y. (Harrington & Gadek 2009). The split between Acer and Dipteronia has been dated to (98-)78(-63.5) m.y.a. (Renner et al. 2007b).

Ecology. The largely neotropical Paullinieae (Sapindoideae), with 8 genera including Serjania and Paullinia, contain one third of the species in the family. Many are vines and have trunks with several vascular cylinders that soon become independent of one another (Tamaio & Angyalossy 2009). Sapindaceae, along with Bignoniaceae and Fabaceae, are the major components of the viny vegetation of the Neotropics (e.g. Gentry 1991).

Pollination Biology. Species of Acer like A. rubrum are known for having very labile breeding systems. Renner et al. (2007b) studied breeding systems in the genus and suggested that dioecy evolved several times.

Chemistry, Morphology, etc.Aesculus has large bud scales, Billia
has naked buds, but both branch from the previous flush. "Ordinary-looking" stipules are known only from climbing species like Serjania, but leaflets looking like stipules (pseudostipules) occur elsewhere in the family.

Radlkofer (1892-1900) shows Serjania as having strongly obliquely symmetric flowers,
with the odd gynoecial member abaxial on the plane of symmetry. The abaxial
corolla member is absent, but the stamens are abaxial, the two adaxial(?)-lateral members being
missing. The petals of Sapindaceae are often rather complex, and have a similarly complex set of terms used to describe them. In Acer, the samaras are shown as being oblique by Schnizlein (1843-1870), while Ronse de Craene (2010) depicts gynoecial orientation as varying within an inflorescence.

Brizicky (1963) reported that the ovules may be epitropous; those of Koelreuteria and other taxa are both epitropous (the lower ovule) and apotropous (the upper ovule)
in the same loculus (Mauritzon 1936; Danilova 1996). Corner (1976) noted that the outer integument of Nephelium lappaceum was slightly thinner than the inner integument, and that there was a definite funicle in Aesculus, at least after fertilization.

The
fruit can look like a follicle when only one carpel develops; dehiscence is, however,
down the abaxial side and rudiments of other carpels are sometimes visible. In many Sapindaceae (and some Anacardiaceae) the pericarp grows much faster than the seed, so what seem to be almost mature fruits can contain seeds that are still very small. Turner et al. (2009) document a water gap near the hilum in the hard seeds of Dodonaea. It has been suggested that the base chromosome number for Sapindaceae is x = 7 (Ferrucci 1989).

For general accounts, see Radlkofer (1890, 1933 to 1934, etc.) and Acevedo-Rodríguez et al. (2011), for chemistry, see Hegnauer (1964, 1966, 1973, 1989, 1990, also under Aceraceae and Hippocastanaceae), for wood anatomy, see Klaassen (1999) and Agarwal et al. (2005), for epidermal features, see Cao and Xia (2008) and Pole (2010), for floral morphology of Koelreuteria, see Ronse Decraene et al. (2000b), that of Handeliodendron, Cao et al. (2008), of Acer, etc., Leins and Erbar (2010), and for that of Xanthoceras, Zhou and Liu (2012), for nectaries, which may have three vascular traces, see Solis and Ferucci (2009) and Zini et al. (2014), for pollen, see Muller and Leenhouts (1976), for embryology, Nair and Joseph (1960) and Tobe and Peng (1990),
for chromosome numbers, Lombello and Forni-Martens (1998), for chromosome size, see Ferrucci (1989), for fruits of Paullineae, see Weckerle and Rutishauser (2005), for seeds, see Guérin (1901), van der Pijl (1955) and Turner et al. (2009: germination), and for genome size, Coulleri et al. (2014: not much correlation with anything).

Phylogeny. Preliminary studies suggested that Xanthoceras, with simply 5-merous, polysymmetric flowers (but eight stamens), ovules arranged in parallel (see also Magonia), and complex, golden nectaries borne outside the eight stamens, might be
sister to all other Sapindaceae, general relationships being [Xanthoceras [[erstwhile Aceraceae + Hippocastanaceae] the remainder of the family]]]
(see Klaassen 1999; Savolainen et al. 2000a; Soltis et al. 2007a). Recent two-gene studies (Harrington et al. 2005, 2009: information about secondary structure of ribosomal DNA, extensive sampling in Dodonaeoideae but no Sapindoideae) have largely confirmed these results. Harrington et al. (2005) found that Xanthoceras was not sister to the rest of the family in single gene analyses, being somewhat embedded, but without strong support; it was only in the joint analysis that is was sister to all other Sapindaceae with 70% bootstrap and ³95% posterior probability (see also Buerki et al. 2010a, 2010b, support still very low). Early morphological analyses (Judd et al. 1994) suggested a rather different set of relationships.

For extensive phylogenetic studies of the family, see Buerki et al. (2009, 2010b: 81 and 104 genera respectively); Delevaya and Koelreuteria are successively sister to the rest of Sapindoideae (Buerki et al. 2013b). For the phylogeny of Acer, see Li et al. (2006) and Renner et al. (2007b), and for that of Dodonaea, see Harrington and Gadek (2010), and for relationships around Cupania, see Buerki et al. (2012a).

Classification. The phenetically distinctive Aceraceae and Hippocastanaceae are here included in Sapindaceae, with which they have much in common; Buerki et al. (2010b) prefer to recognize them (and Xanthoceras, as Xanthoceraceae) as families. For subfamilies, see Buerki et al. (2009). There is extensive polyphyly of the classically-recognized tribes (Buerki et al. 2010b), while generic limits in the Cupania group (Sapindoideae) are unclear (Buerki et al. 2012a).

Previous Relationships. Sapindaceae are chemically similar in some respects to Fabaceae, e.g. both have non-protein amino acids (for a summary, see Fowden et al. 1979), and both have compound leaves, their seeds may be arillate, etc.,
but they are not closely related.

Hartl (1958) suggested that there were similarities between Rutaceae and Simaroubaceae in fruit (endocarp) anatomy; he did not include other Sapindales in his comparison. Rutaceae and Simaroubaceae are both reported to have embryo sac haustoria (Mickesell 1990) and carboline alkaloids and canthinones (Waterman & Grundon 1983).

[Simaroubaceae + Meliaceae]: ?

Age. An age for this node is suggested as (48-)44, 40(-36) m.y.a. (Wikström et al. 2001).

Simaroubaceae can be recognised because the twigs have conspicuous
pith - herbarium specimens are often notably light - and the bark is bitter,
even when the plant has been dried; the leaflets of the odd-compound leaves often have rather coarse, blunt, teeth and flat
glands on the lower surface, sometimes close to the margin, and the leaf rhachis
collapses at the nodes. The flowers are rather small, the petals usually barely exceeding the sepals. The fruits are often separate drupelets or samaras.

Evolution.Divergence & Distribution. Most diversification of Simaroubaceae has been in the Caenozoic (Clayton et al. 2009). Despite (or because of?) the fairly good fossil history of the family in the northern hemisphere, the biogeographic hisory of Simaroubaceae is of considerable complexity with much dispersal (and some extinction) needed to explain the current distribution of taxa (Clayton et al. 2009, see also 2007b).

Indeed, in the map above it is obvious that distributions of some genera in the past and the present are very different. Fossil Ailanthus is widespread in the Eocene ca 52 m.y.a.; it has not been recorded from the Palaeocene (Corbett & Manchester 2004; see also Clayton et al. 2009: the fossil history of Leitneria and Chaneya, the latter not certainly Simaroubaceae). Fruits identified as Leitneria, a genus now endemic to the U.S.A., have been found in eastern Siberia (Ozerov 2012).

I have put in some phylogenetic structure above because of its effect on our understanding of character evolution; the [Quassia [Samadera + Simarouba etc.]] clade has some distinctive features, but it is well embedded in the family, so these features are not family-level apomorphies.

The adult plant of Holacantha is basically a giant, intricately-branched branched thorn; the leaves are reduced to scales.

Although the carpels may seem more or less free, there is often only a single style. The gynoecium of Leitneria is described as having a single carpel with two ovules, of which only one is fertile (Tobe 2011a). Even in taxa with unitegmic ovules, the axis of the embryo and that of the micropyle are offset at a sharp angle, hence the latter can be thought of as being zig-zag. There are reports of other than porogamous fertilization in the family (c.f. Anacardioideae: Rao 1970).

Phylogeny. The overall relationships, [Picrasma etc. [Ailanthus [Soulamea, etc. [Nothospondias* [Picrolemma [Quassia* [Samadera* + Simarouba etc.]]]]]]] are are mostly quite well supported, although support for the first clade is not that strong and that for some nodes along the backbone (the genera that might move have an asterisk) could be improved (Clayton et al. 2007a, esp. b; 2009). Leitneria is well embedded in the family (Clayton et al. 2007b) and has embryological similarities with Brucea, in the same clade (Soulamea, etc.).

The very poorly-known Gumillea (ex Cunoniaceae) might be in Simaroubaceae, although the stamens do not appear to have scales and there are many ovules per carpel - the latter feature in particular is rather odd for any putative sapindalean plant. It has stamens alternate with the petals, so making membership in Picramniales unlikely (and ovule number also militates against this, too).

Classification. Note the demise of Leitneriaceae, the only family previously thought to be restricted to the continental U. S. A. - alack! For the dismemberment of Quassia, see Clayton et al. (2007b).

Previous Relationships. Simaroubaceae have been very difficult to delimit, and molecular data suggest the excision of Suriana and its relatives (see Fabales-Surianaceae), Harrisonia (Rutaceae), and
Picramnia and Alvaradoa (Picramniales-Picramniaceae) (e.g. Fernando
et al. 1995).

Age. The age for this node is estimated at (28.2-)19.8(-12.1) m.y.a. (Pfeil & Crisp 2008) or ca 30 m.y.a. (Muellner et al. 2007.

Synonymy: Amyridaceae Kunth, Aurantiaceae Jussieu, Citraceae Roussel

Rutaceae are recognisable because of their often opposite, compound
and punctate leaves; their cymose inflorescences; their flowers, with the stamens
often arranged in a ring, thick filaments, conspicuous disc at the base of the
ovary, and expanded stigma, are quite distinctive. Although the fruits are
variable, many have a glandular-punctate pericarp, and/or they may be dry, deeply
lobed, and dehisce to reveal black and shiny seeds.

Evolution.Divergence & Distribution. For the early Caenozoic fossil history of what are now East Asian endemic Rutaceae, see Manchester et al. (2009); Gregor (1989) discussed Caenozoic fossil seeds.

For other dates of diversification within Rutaceae, especially Aurantieae, see Pfeil and Crisp (2008; c.f. in part Muellner et al. 2007); the family is relatively young, and distributions are unlikely to be much affected by continental drift (but c.f. Kubitzki et al. 2011; Hartley 2001a, 2001b; Ladiges & Cantrill 2007).

Ca 250 species of Diosmeae are restricted to South Africa, largely to the Cape Floristic Region (Trinder-Smith et al. 2007). About 1/4 (400< spp.) of the species in the family are to be found in Australia (see Bayly et al. 2013b for a phylogeny), where most have narrow distributions; movement seems to have been from rainforest habitats to more sclerophyllous/xerophytic vegetation, but there were only four or five of these shifts (Bayly et al. 2013b). There is a major radiation of Melicope on Hawaii of 50+ species, and from Hawaii there seems to have been dispersal to the Marquesas Islands; the source area is likely to be in the general Australia-New Guinean region (Harbaugh et al. 2009b; Appelhans et al. 2014a). Appelhans et al. (2014b) suggested that the black shiny seeds common in the Acronychia-Melicope clade were a key innovation; the exotesta is edible (birds), and this clade has about 17x as many species as Tetracomia and the Euodia clade, successively its sisters.

Appelhans et al. (2011: many original observations!) plotted a number of morphological characters on the tree, focussing on Cneoroideae; the clade is morphologically quite heterogeneous - like the rest of the family. See also Bayly et al. (2013b) for morphology in Australasian members of the family.

Seed Dispersal. For black, shiny, fleshy seeds in the Acronychia-Melicope clade, see Bayley et al. (2013) and Appelhans et al. (2014b). Diosmeae (South African) and Boronia and relatives (Australian) both have seeds with elaiosomes that are endocarpial in origin and are dispersed by ants (Kubitzki et al. 2011; Bayley et al. 2013).

Plant-Animal Interactions. Rutaceae have exceptionally diverse secondary metabolites, some of which (essential oils, coumarins, etc.) are similar to those in Apiaceae, Asteraceae, Papaveraceae, etc. (Hegnauer 1971; Kubitzki et al. 2011), while their alkaloids are like those found in some magnoliids - and are produced via nine or more
different biosynthetic pathways. Thus 1-benzyltetrahydroisoquinoline alkaloids are found in a small group of related Rutoideae, and also in Papaveraceae (and a couple of other families), a distribution that has exercised phytochemists' imaginations in the past (Kubitzki et al. 2011).

Caterpillars of Papilionidae-Papilionini butterflies are notably common on Rutaceae, and about ca 1/3 of the records are from this family, and 80% of the ca 550 species of Papilio will eat Rutaceae (Zakharov et al. 2004). Like the magnoliids, e.g. Aristolochiaceae, on which other Papilionidae are found, it is the alkaloids that attract the butterflies. Rutaceae may have been the original food plants for Papilio, since even those species which now eat Magnoliales will eat Rutaceae if they have to (Zakharov et al. 2004, but c.f. Fordyce 2010; see also Berenbaum & Feeney 2008; Simonsen et al. 2011; Condamine et al. 2011).

Chemistry, Morphology, etc. Rutaceae as circumscribed here are a variable group. For their diverse secondary metabolites, see Hegnauer (1971) and Kubitzki et al. (2011). Da Silva et al. (1988) surveyed the secondary metabolites, suggesting that an overhaul of the infrafamilial classification was in order. Adsersen et al. (2007) noted the value of prenylated acetophenones as a marker for Xanthoxyleae (inc. Melicope, etc.), and Braga et al. (2012) the distinctive dihydrocinnamic acid derivates common in Rutoideae.

Prickles of Zanthoxylum can be in the stipular position.

Rutaceae are particularly variable in flower and fruit (Boesewinkel 1980b). Peltostigma
has a floral formula K3 C3 A9 G [?5], and looks almost lauraceous; Pilocarpus
has an erect raceme and the calyx is reduced to a rim. Monosymmetry is scattered in the family, occurring in Dictamnus (relationships uncertain) and Erythrochiton, for example. Kallunki (1992) illustrates the flowers of Erythrochiton fallax as having the median sepal adaxial, but their exact orientation and how they are held in nature is unclear since the inflorescence can be pendulous and up to 1.5 m long. The flowers of Galipeinae (the Angostura alliance of Kubitzki et al. 2011), to which Erythrochiton (but not the tube-forming Correa) belongs, may have only two stamens plus staminodes, a connate corolla, filaments connate and forming a tube, or a tube formed by the serial adnation of filaments and petals; variation in gynoecial development is also considerable (Pirani & Menezes 2007; el Ottra et al. 2011, esp. 2013). Wei et al. (2011) thought that the plesiomorphic condition for Rutaceae was to have have five stamens.

Triphasia has G [3], the odd member being adaxial, and the same is true of Cneorum tricoccon, which has 3-merous flowers (see Caris et al. 2006 for floral development). Carpel (stylar) fusion may be postgenital (Gut 1966). Both apotropous and epitropous ovules are recorded from the family. In bitegmic taxa, either integument may be slightly thicker than the other (e.g. Corner 1976). Nucellar polyembryony is quite widespread. The endocarp divides periclinally during development (Hartl 1957), resulting in a pronounced layering of the mature capsule, especially in Rutoideae.

Phylogeny. In a two-gene analysis, the [[Spathelia + Dictyoloma] [[Cneorum + Ptaeroxylum] Harrisonia]] clade was sister to all other Rutaceae (Chase et al. 1999), although the position of Harrisonia - sequences from only one gene - was somewhat unclear (see also Groppo et al. 2008, 2012). Spathelia (chromones) and Dictyoloma (C valvate) are a strong pair; secretory cavities are reported from them (Groppo et al. 2008). Jadin (1901) had noted that anatomically Harrisonia was rather different from other Simaroubaceae (in which it was then placed) in its heterogeneous pith and its lack of medullary secretory canals. Although it does not seem to have pellucid foliar gland dots, Fernando and Quinn (1992) found secretory cavities in the fruits while Waterman (1993) noted that the genus contained no quassinoids, which are unique to Simaroubaceae. Fernando et al. (1995) suggested that its removal to Rutaceae was justified on both molecular and morphological grounds. Razafimandimbison et al. (2010) also found a weakly/moderately supported clade that included the old Ptaeroxylaceae and in which [Spathelia + Dictyoloma] were sister to the rest. Appelhans et al. (2011: denser sampling, five chloroplast genes, 2012a) again found this basic topology; support for the groups was strong, and within the two major clades in Cneoroideae, both strongly geographically circumscribed, Sohnreyia was sister to other neotropical taxa and Harrisonia sister to other palaeotropical taxa (Appelhans et al. 2012a). Morton (2015) found the group to be paraphyletic and basal to the rest of the family, although it was not the focus of her study. For this clade, see Cneoroideae above.

Other genera in the family form a single clade, and the classical subfamilies other than Aurantioideae are variously mixed up in it. Hartley (e.g. 1981, 1997, 2001a, b) had early suggested some generic realignments in Malesian-Pacific Rutaceae that largely ignored the then-conventional subfamilies; this work has held up fairly well in molecular studies. Neither the large genus Melicope nor Acronychia are monophyletic (Appelhans et al. 2014b). Salvo et al. (2008, also 2010; Groppo et al. 2008, 2012) found that Dictamnus was widely separate from the other members that had been included in Ruteae, rather, it linked with Casimoroa and Skimmia (see also Morton & Telmer 2014; Morton 2015). Rutaceae not included in the previous three subfamilies formed a clade [Dictamnus et al. [[Pilocarpus + Ravenia] The Rest]]] (see Poon et al. 2007; Groppo et al. 2008, 2012; Salvo et al. 2010; Morton & Telmer 2014) or were part of a polytomy including them (Bayly et al. 2013b; Morton 2015). One large clade is mostly Old World-Oceanian in distribution, although it includes the Chilean Pitavia (Groppo et al. 2012). Flindersia and relatives have secretory cells in the stem only and septifragal capsules that are perhaps reminiscent of Meliaceae,
but their furoquinoline alkaloids, schizogenous cavities, and subterete filaments are consistent with a position in Rutaceae. Euodia and relatives form another moderately to well supported clade (Salvo et al. 2010; Groppo et al. 2012) perhaps sister to a clade including most of the Australian taxa that were included in the old Boronieae (Bayly et al. 2013b; Morton 2015), and a [Zanthoxylum + Toddalia] clade (Groppo et al. 2012: support poor), in turn sister to the Flindersia group (Bayly et al. 2013b). A final clade (see e.g. Bayley et al. 2013b) includes the North American Ptelea, a largely African Diosmeae (for relationships, see Trinder-Smith et al. 2007), and a largely Central and South American Galipeinae (for relationships, see Kallunki & Groppo 2007). However, support for some of these groups, and of relationships between and within them, is still rather weak (Groppo et al. 2012; Bayly et al. 2013b; Morton & Telmer 2014). For relationships in the largely Australian Zieria, see Morton (2015).

Savolainen et al. (2000b) suggested that Lissocarpaceae
should be included here, but a position in Ericales-Ebenaceae is now strongly supported (e.g. Berry et al. 2001).

Classification. Although Cneoroideae (also called Spathelioideae in recent literature) form a fairly distinct group, inclusion within Rutaceae s.l. is reasonable (Groppo et al. 2008, 2012; Appelhans et al. 2011). Some of the fruit characters previously used to distinguish subfamilies in other Rutaceae are proving unreliable in delimiting major clades (e.g. see Hartley 1981; But et al. 2009), and tribal and subfamilial limits for the most part need overhauling (e.g. Salvo et al. 2008; Poon et al. 2008). For a tribal classification of Cneoroideae, see Appelhans et al. (2011), and for the beginnings of a classification of the rest of the family, see Groppo et al. (2012). For the rest, I tentatively follow the subbfamilial framework suggested by Morton and Telmer (2014), although the sampling is rather slight (34 species, even if they do represent all subfamilies and tribes), bolstered by that in Groppo et al. (2012), etc..

Previous Relationships. Cronquist (1981) placed Cneoraceae in his Sapindales which included Rutales more or less as above and then some; Airy Shaw (1966) associated Kirkia
with Ptaeroxylaceae, but with hesitation. Hegnauer (1990) included Ptaeroxylum in Meliaceae, although he noted it was chemically more similar to Rutaceae. Thorne (1992) included Harrisonia (ex Simaroubaceae), although no reasons were given.

Botanical Trivia. Ehrlich and Raven (1964) predicted, based on the caterpillars that ate it, that Ptaeroxylon would be found to have alkaloids - it has (e.g. Muscarella et al. 2008).

Meliaceae are recognisable by their usually spiral and odd-compound
leaves with well-developed leaf buttresses, i.e. the leaf bases are swollen and more or less elongated vertically. The leaflets are often opposite and dry thin and brittle, with
little in the way of tertiary venation evident. The bark may smell - sweet, like garlic, etc. - and milky exudates occur sporadically. The flower buds are often longer
than broad, with petals much longer than the sepals, and most members have a staminal tube the mouth of which is blocked by the large stigma. The fruits
and seeds are usually quite large. [Photo - Flower, Fruit.]

Evolution.Divergence & Distribution. Muellner et al. (2006) discussed the biogeography of the family, suggesting its origin in Africa and subsequent dispersal. For the biogeography of Aglaia, see Muellner et al. (2008b) and Grudinski et al. (2014a), the latter suggesting Oligocene-Miocene rather than Eocene diversification; movement was from West Malesia eastwards.

Ecology & Physiology. Although only a small family, Meliaceae make up 17% of all trees >10 cm d.b.h. in Sumatra (Mabberley 2011).

Pollination Biology & Seed Dispersal. Most Meliaceae have a well-developed floral tube which is formed by the connation of the filaments - a rather uncommon way of forming a tube. The pistillode in staminate flowers is well developed, the result being that staminate and carpellate flowers are very similar functionally, although the staminal tube in the former is often somewhat narrower. The whole apex of the style is commonly more or less massively swollen and is sometimes involved in secondary pollen presentation, as in Vavaea (Ladd 1994).

Animal dispersal is common in Meliodeae; for detailed studies of the dispersal of arillate-type seeds of Malesian Aglaia, see Pannell and Koziol (1987). Wind dispersal is common in Cedreloideae.

Vegetative Variation.Munronia is ± herbaceous. Most species of Guarea (tropical America) and Chisocheton (Malesia), both Melioideae, have indefinitely growing
leaves. In Guarea the apical part of the leaf is shoot-like in its gene expression (Tsukaya 2005). The leaves of Chisocheton can be rooted (Fisher & Rutishauser 1990), and then they continue to grow for a long time, although I do not know that a tree has ever been produced from a leaf. Species of Chisocheton such as C. pohlianus have an epiphyllous inflorescence, flowers appearing between the leaflets; specimens have been misidentified as Rubiaceae! Capuronianthus (Swietenioideae) has opposite, compound leaves, while the simple-leaved Vavaea and Turraea (both Melioideae)
look rather unmeliaceous except when in flower; the leaves of the latter genus can even be two-ranked and lack articulations.

Chemistry, Morphology, etc. Although it was thought that the two subfamilies could be separated by their limonoid types, work on Quivisianthe (Melioideae) suggests that the distinction may not be that simple (Mulholland et al. 2000). Sieve tube plastids with protein crystalloids
and starch occur in Melia and Azederach. Walsura often has leaflets with ± pulvinate petiolules and prominent
reticulate venation.

Gouvêa et al. (2008b) drew the flowers of Swietenia as being inverted; carpellate flowers are the first to be produced in the cymose inflorescences. The filaments of Vavaea are largely free, as are those of Cedrela and Toona (Cedreloideae-Cedreleae). Indeed, Cedreleae are rather different florally from other Meliaceae, but features found there such as more or less free stamens may be derived, not plesiomorphous as one might think (c.f. Gouvêa et al. 2008a). In Walsura the stamens are also more or less free, and the fruit is often 1-seeded. There is considerable variation in seed morphology and development (e.g. Wiger 1935; Corner 1976), even within the subfamilies, and this will have to be integrated with the phylogeny as it develops.

Within Melioideae, Melieae (probably including Owenia) are sister to the rest, but with only moderate support; relationships along the backbone of the rest of the rather pectinate ITS tree are poorly supported, but rather better resolved by rbcL data (Muellner at al. 2008a). For relationships in Aglaia, see Muellner et al. (2005) and Grudinski et al. (2014a, b), in Chisocheton, see Fukuda et al. (2003), and in Neotropical Cedreleae, see Muellner et al. (2009).

Classification. Cedreloideae used to be called Swietenioideae. For a generic monograph, see Pennington and Styles (1975), for a monograph of Neotropical Meliaceae, see Pennington (1981), and for a monograph of Aglaia, see Pannell (1992). The connection between species limits in the latter genus and phylogenetic relationships as they are currently understood is somewhat unclear (Grudinski et al. 2014b).